Extension arm

ABSTRACT

An extension arm ( 1 ) is provided, especially a pivotal and adjustable-tilt extension arm for a supporting system, for the suspended fixing of preferably medial devices ( 2-5 ) through a joining element ( 6-9 ) fastened to a fixing piece ( 17 ) of the extension arm ( 1 ). The extension arm includes a securing element ( 34 ), which is guided through an opening ( 35 ) of the fixing piece ( 17 ) and secures the fastening of the joining element ( 6-9 ) to the fixing piece ( 17 ) by engaging inside a groove ( 36 ) of the joining element ( 6-9 ). The extension arm also includes a securing bush ( 26 ), which at least partially surrounds the fixing piece ( 17 ) and the joining element ( 6-9 ) and which secures the securing element ( 34 ) through the use of a spring element ( 40 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an extension arm, particularly a pivotable andinclinable extension arm, for a supporting system, for the suspendedattachment of preferably medical devices.

2. Discussion of the Prior Art

A known extension arm comprises a horizontal or spring arm, which isattached by means of a connecting piece of the extension arm to aceiling mount which is preferably mounted on the ceiling of a room inwhich the devices are used. Here, the connecting piece is connected tothe horizontal arm by way of a hinge joint, so that the horizontal armcan be inclined relative to the connecting piece with respect to thehorizontal. Moreover, the extension arm has an attachment piece which isconnected by means of a joint piece to the horizontal arm and on whichfor example medical equipment, such as an operating light or aprotective X-ray shield may be attached. In order to enable a pluralityof different devices to be attached to the extension arm, the connectionis designed to be releasable, which means that it is necessary to securethe connection in order to prevent the connection from being releasedunintentionally. The known securing means has a securing element whichengages in a groove in the connecting element connected to the device,thus blocking withdrawal of the connecting element from the attachmentpiece. Here, the connection is designed in such a way that part of theweight of the device acts on the securing element in the assembledcondition.

The known extension arm has a plurality of disadvantages. In the courseof time, the securing element can escape from the groove with the resultthat it now engages only partially in the groove and the securing forceis considerably reduced in the event of maloperation. If the securingelement engages only partially in the groove, the problem moreoverarises that—if the device to be attached is very heavy—the load fromonly part of the weight of the device is sufficient to bend the securingelement or damage the connecting element in the region of the groove asa result of the load on the securing element in the region of the groovein the connecting element. During dismantling, e.g. dismantling for thepurpose of attaching another medical device, this can also result in itno longer being possible to remove the securing element from the groovein the connecting element—or it only being possible to remove it withdifficulty—with the result that substantial repair measures arerequired. There is moreover a risk of the securing element not engagingevenly in the groove in the connecting element, with the result that thesecuring force is relatively small and the problems discussed abovearise accordingly.

SUMMARY OF THE INVENTION

The object of the invention, therefore, is to provide an extension armin which the functionability of the securing mechanism is ensured and,in particular, the cooperation between the securing element and theconnecting element is improved, and furthermore to devise a process bymeans of which this secure connection can be produced.

The object is achieved by an extension arm in which a spring element ispushed at least partially between a securing bushing and the securingelement. Furthermore, there is also provided a method for assembling apreferably medical device by use of the connecting element on anextension arm.

The extension arm according to the invention is advantageous in that thesecuring element for securing the attachment of the connecting elementon the attachment piece is held in the groove of the connecting elementby the spring element, thus achieving a reliable securing action wherebythe securing element is prevented from escaping from the groove in theconnecting element and an uneven load on the securing element in theregion of the groove is avoided, with the result that the extension armis more secure and is particularly suitable for relatively greatweights, i.e. for heavy devices, acting on the attachment piece.

Advantageous further developments of the extension arm described in thedetailed description as set forth hereinbelow.

At least one securing screw is advantageously provided, which is screwedinto the securing bush and on which the spring element is at leastpartially supported. Thus, the pre-tension force of the spring elementcan be adjusted and particularly additionally increased, the securingscrew additionally being acted upon by a spring force from the springelement, so that the securing element is additionally prevented frombeing released unintentionally.

It is advantageous that the securing screw cooperates with the securingelement to block a displacement of the securing bush relative to thesecuring element. This prevents the securing bush from being displacedwith respect to the attachment piece in such a way that the securingelement and/or further securing or attachment means, e.g. a cylinderpin, are not secured.

It is advantageous that the securing bush has a cutout in which thesecuring element and the spring element are partially arranged. Thus,the position of the securing element and/or the position of the springelement can be additionally fixed, so that in particular tilting of thesecuring element or the spring element in a plane perpendicular to theaxis of the attachment piece is prevented.

The spring element is advantageously constructed from a preferably metalspring strip. It is advantageous here that the spring element has afirst portion and a second portion which, in a relaxed condition of thespring element, are arranged at least substantially perpendicular to oneanother. This results in a spring element which is easy to manufactureand which generates a large spring force in the assembled condition ofthe extension arm.

It is furthermore advantageous that the first portion is longer than thesecond portion. Thus, the spring element can be advantageously guided inbetween the securing bush and the securing element and aligned betweenthem. Advantageous alignment of the spring element in the cutout in thesecuring bush is particularly possible.

It is advantageous that the second portion is constructed to be such alength that it projects at least approximately over the lower edge ofthe securing bush in the assembled condition of the extension arm. Thus,when assembling the extension arm, it is particularly easy to determinewhether the spring element is assembled correctly. This moreover enablesthe assembly personnel to carry out a simple check as to whether thespring element is installed in order to ensure the security of theextension arm. An essential factor here is that it is not necessary tocarry out dismantling procedures in order to check whether the springelement is installed and whether it has been arranged correctly; insteadthis is possible merely by means of external examination.

The first portion and the second portion are advantageously connected bymeans of a U-shaped middle portion which abuts at least partiallyagainst the securing element. Thus, the assembled position of the springelement is fixed in a direction parallel to the axis of the attachmentpiece, thus further simplifying assembly.

It is furthermore advantageous that at least one securing screw isprovided, which is screwed into the securing bush and engages at leastpartially in the U-shaped middle portion of the spring element. Thus,the spring element is additionally secured, the securing bush moreoverbeing secured against displacement in a direction along the axis of theattachment piece.

The inventive process as described herein is advantageous in that thesecuring element is pushed particularly deep into the groove in theconnecting element in that the securing spring is pushed in between thesecuring bush and the securing element, the securing elementadditionally being acted upon by a holding force in that the securingspring is pre-tensioned by means of the securing bush as a result ofdisplacing this latter along the attachment piece.

Advantageous further developments of the process are described infurther detailed hereinbelow.

It is advantageous that a securing screw is furthermore screwed into thesecuring bush in order to block displacement of the securing bush andadditionally tension the securing spring.

It is moreover advantageous that the connecting means connecting theconnecting element to the attachment piece is inserted through anopening in the securing bush.

BRIEF DESCRIPTION OF THE DRAWING

Exemplary embodiments of the invention are illustrated in simplifiedmanner in the drawing and explained in more detail in the descriptionbelow. There is shown:

FIG. 1 an exemplary embodiment of an extension arm according to theinvention, with a plurality of medical devices which can be connected tothe extension arm, in a partially exploded illustration;

FIG. 2 the section denoted by II in FIG. 1;

FIG. 3 a detail of the extension arm according to the invention duringassembly of the spring element;

FIG. 4 a detail of the extension arm according to the invention afterassembly of the spring element; and

FIG. 5 a detail of the extension arm according to the invention in theassembled condition, in a partially sectional illustration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an extension arm 1 for the suspended attachment of devices2-5. For this, each of the devices 2-5 has a connecting element 6-9. Theextension arm 1 and the connecting elements 6-9 are components of asupporting system which enables the preferably medical devices, e.g. aprotective X-ray shield 10 and a display screen 11 to be exchangeablysuspended in a room, the devices being suspended for example on aceiling mount, e.g. in the form of a mounting rail, fixed to theceiling.

The extension arm 1 has a connecting piece 12 which comprises acylindrical pin 13, the extension arm 1 being pivotable about the axisof rotation 14. Moreover, the extension arm 1 has a horizontal arm 16,which is connected to the connecting piece 12 by means of the jointpiece 15 and is pivotable or rotatable about the axis of rotation 14 ofthe pin 13 and inclinable with respect to a horizontal plane orientatedperpendicularly to the axis of rotation 14. The extension arm 1 moreoverhas an attachment piece 17 which is connected by means of a joint piece18 to the horizontal arm 16, so that the attachment piece 17 ispivotable about the axis 19 of the joint piece 18, relative to thehorizontal arm 16.

The horizontal arm 16 can be constructed as a spring arm, as a result ofwhich the weight of a device 2-5 is compensated and the device 2-5remains in the predetermined position.

The invention is described in more detail below, with reference to FIG.2 which shows the section denoted by II in FIG. 1. Elements which havealready been described are provided with corresponding referencenumerals in all figures, thus making repeated description unnecessary.

For transporting the extension arm 1, the protective cap 25 is installedin the attachment piece 17 at the factory in order to deliver theextension arm 1 in a condition similar to that required for attaching adevice 2-5, so that, as a result of the preparatory dismantling of theextension arm 1, it becomes clear to the assembly personnel how theextension arm 1 is to be initially assembled during connection to adevice 2-5. It is thus possible to prevent assembly errors which mayarise for example as a result of misunderstanding the assemblyinstructions.

The attachment of the device 6 or 8 to the extension arm 1 is describedbelow. First of all, the securing bush 26 is pushed onto the attachmentpiece 17 and then the connecting element 6, 8 of the device 2, 4 ispushed into the attachment piece 17, the insertion depth being fixed bythe stop 27 which abuts against the underside 28 of the attachment piece17. Care should be taken here to arrange the elongated cutout 29 in theattachment pin 30 of the connecting element 6 opposite the cutout 31 inthe attachment piece 17. In a suitable first position of the securingbush 26, the connecting means 32, which is constructed in this exemplaryembodiment as a cylinder pin, can be inserted through the opening 33 inthe securing bush 26 into the cutout 31, through the elongated cutout 29in the connecting element 6, 8 and into a cutout in the attachment piece17, which is opposite the cutout 31. Thus, the connecting element 6, 8is connected to the attachment piece 17 by means of the connecting means32, as a result of which the device 2, 4 is attached to the extensionarm 1 in suspended manner.

To secure this attachment, the securing element 34 is inserted into agroove 36 in the connecting element 6, 8 through the opening 35 in theattachment piece 17 whilst the securing bush 26 is in a position closeto the first position. The securing element 34 has a bent part 37 and anose-shaped part 38. The bent part 37 is inserted at least partiallyinto the groove 36, the radius of curvature of the bent part 37 of thesecuring element 34 being adapted to the inside radius of the peripheralgroove 36. The first portion 39 of a spring element 40 is placed overthe nose-shaped part 38 of the securing element 34, a stop for thespring element 40 against the nose 34 being produced by a U-shapedmiddle portion 41. After the spring element 40 has been pushed in, thesecuring bush 26 is displaced along the attachment piece 17 into asecond position by way of the second portion 42 of the spring element40, the securing spring 40 being pre-tensioned in that the secondportion 42 is bent back.

In the second position of the securing bush 26, a securing screw 46 isscrewed into the threaded bore 45 in the securing bush 26 so that, onthe one hand, the spring element 40 is at least partially supported onthe securing screw 46 and, on the other, displacement of the securingbush 26 relative to the securing element 34 or relative to theattachment piece 17 is blocked as a result of the securing screw 46engaging in the U-shaped middle portion 41 of the spring element 40. Afurther securing screw 47 is furthermore provided, which is guidedthrough a bore in the securing bush 26 and engages in a threaded bore inthe attachment piece 17 in order to additionally secure the securingbush 26, particularly against twisting with respect to the axis 48 ofthe attachment piece 17. A plastic cap 49 is provided for closing theopening 33.

As an alternative to attaching the device 2 or 4 to the attachment piece17 by means of the connecting means 32, in the case of the extension armaccording to the invention it is also possible to provide otherattachments which are secured accordingly.

For example, the devices 3 and 5 can be connected to the extension arm 1in that a screw is screwed into the connecting element 7, 9 through anopening corresponding to the opening 33, it being preferable to providea plurality of such screws. The securing bush 26 accordingly preventsthe screw from being released, and the connecting means 32 is alsoprevented from becoming displaced. It is therefore clear that theattachment between the connecting element 6-9 and the attachment piece17 can be secured according to the invention irrespective of theconcrete design of the attachment.

The securing bush 26 has an approximately rectangular cutout 50, thespring 40 being guided in between the securing bush 26 and theattachment piece 17 in the region of the cutout 50. During assembly, itis thus easier to recognise where the spring 40 is to be assembled.Moreover, the cutout 50 defines a lower edge 51 of the securing bush 26.The second portion 42 of the spring element 40 is constructed to be sucha length that it projects at least approximately over the lower edge 51of the securing bush 26 in the assembled condition of the extension arm1, as a result of which it is readily possible to detect from theoutside whether the spring element 40 has been mounted correctly. Thus,as a result of the cutout 50 and the correct choice of length for thesecond portion 42 of the spring element 40, it is easily possible tocheck the securing action according to the invention.

FIG. 3 shows a detail of the extension arm 1, in which the securing bush26 is located in the first position.

In order to mount the securing bush 26 in the first position on theattachment piece 17 of the extension arm 1, it has been moved along theattachment piece 17 in the direction 60 of the horizontal arm 16. Inthis position, the securing element 34 has been pushed through theopening 35 in the attachment piece 17 and into the groove 36 in theconnecting element 6 through the cutout 50. The nose-shaped part 38 ofthe securing element 34 is partially visible in FIG. 3. When thesecuring screw 46 is removed, the spring element 40 is pushed over thenose-shaped part 38 of the securing element 34 in between the securingbush 26 and the attachment piece 17 until the U-shaped middle portion 41abuts against the nose-shaped part 38 of the securing element 34, asshown in FIG. 4.

The second portion 42 of the spring element 40 is arranged substantiallyperpendicularly with respect to the first portion 39, so that the secondportion 42 protrudes substantially perpendicularly from the attachmentpiece 17.

As shown in FIG. 5, the securing bush 26 is then displaced along theattachment piece 17 in the direction 65, which is opposite to thedirection 60, into a second position, the second portion 42 of thespring element 40 being bent to the attachment piece 17 as a result ofthe action of the lower edge 51 of the securing bush 26 in order topretension the spring element 40. In the second position shown in FIG.5, the threaded bore 45 is located on the side of the second portion 42of the spring element 40, as seen from the securing element 34.

Therefore, in this position, the securing screw 46 engages in thethreaded bore 45 in the U-shaped middle portion 41 of the spring element40 when it is screwed in, thus blocking a displacement of the securingbush 26 along the attachment piece 17 in opposition to the direction 65.Since the securing bush 26 abuts at the lower edge 66 against the stop27 of the connecting element 6, a displacement of the securing bush 26along the attachment piece 17 in the direction 65 is moreover blocked.Thus, the displacement of the securing bush 26 along the attachmentpiece 17 is blocked in both directions and a release of the securingelement 34 and, where applicable, the connecting means 32, is preventedunder all circumstances.

In order to enable the securing element 34 and the spring element 40 tobe received, the securing bush 26 has a cutout 67 whereof the width issomewhat greater than the width of the strip-shaped spring element 40,so that the spring element 40 is guided into the cutout 67 uponinsertion. Thus, the position of the strip-shaped spring element 40 isproduced by the cutout 67, and, in particular, lateral displacement ofthe spring element 40 is permanently reliably prevented.

The invention is not restricted to the exemplary embodiments described.In particular, the described securing means and the described securingprocess can be used for a plurality of different attachment options.

What is claimed is:
 1. An extension arm (1), particularly a pivotableand inclinable extension arm for a supporting system, and for thesuspension of an attachment, preferably medical devices (2-5), theextension arm comprising: means for attaching a connecting element (6-9)to an attachment piece (17), a securing element (34), which is guidedthrough an opening (35) in the attachment piece (17), for securing theconnecting element (6-9) on the attachment piece (17) by engaging agroove (36) in the connecting element (6-9), a securing bush (26), whichsurrounds the attachment piece (17) and the connecting element (6-9) atleast partially, for securing the securing element (34), and a springelement (40), which is at least partially supported on the securing bush(26) to hold the securing element (34) in the groove (36) in theconnecting element (6-9), the securing element is held by a pre-tensionforce, wherein the spring element (40) is pushed at least partially inbetween the securing bush (26) and the securing element (34), and atleast one securing screw (46) is provided, which is screwed into thesecuring bush (26) and on which the spring element (40) is at leastpartially supported.
 2. An extension arm according to claim 1,characterised in that the securing bush (26) has a cutout (67) in whichthe securing element (34) and the spring element (40) are partiallyarranged.
 3. An extension arm according to claim 1, characterised inthat the spring element (40) is constructed from a metal spring strip.4. A process for assembling a preferred medical device (2-5) by securingconnecting element (6-9) on an extension arm (1), particularly apivotable and inclinable extension arm for a supporting system in asuspended attached position, the process comprising the steps of: a)assembling a securing bush (26) on an attachment piece (17) of theextension arm (1) in a first position; b) pushing the connecting element(6-9) into the attachment piece (17); c) connecting the attachment piece(17) to the connecting element (6-9) by inserting a connecting means(32), particularly a cylinder pin; d) inserting a securing element (34)into a groove (36) in the connecting element (6-9) through an opening(35) in the attachment piece (17); e) pushing a spring element (40) atleast partially in between the securing bush (26) and the securingelement (34); and then f) displacing the securing bush (26) along theattachment piece (17) into a second position, the spring element (40)being pre-tensioned.
 5. A process according to claim 4, furtherincluding the step of g) screwing a securing screw (46) into thesecuring bush (26) in order to block displacement of the securing bush(26) and additionally tensioning the spring element (40).
 6. A processaccording to claim 4, further including that the connecting means (32)is inserted through an opening (33) in the securing bush (26).
 7. Anextension arm (1), particularly a pivotable and inclinable extension armfor a supporting system, and for the suspension of an attachment,preferably medical devices (2-5), the extension arm comprising: meansfor attaching a connecting element (6-9) to an attachment piece (17), asecuring element (34), which is guided through an opening (35) in theattachment piece (17), for securing the connecting element (6-9) on theattachment piece (17) by engaging a groove (36) in the connectingelement (6-9), a securing bush (26), which surrounds the attachmentpiece (17) and the connecting element (6-9) at least partially, forsecuring the securing element (34), and a spring element (40), which isat least partially supported on the securing bush (26) to hold thesecuring element (34) in the groove (36) in the connecting element(6-9), the securing element is held by a pre-tension force, the springelement (40) is pushed at least partially in between the securing bush(26) and the securing element (34), and wherein there is provided atleast one securing screw (46) which cooperates with the securing element(34) to block a displacement of the securing bush (26) relative to thesecuring element (34).
 8. An extension arm (1), particularly a pivotableand inclinable extension arm, for a supporting system, and for thesuspension of an attachment, preferably medical devices (2-5), theextension arm comprising: means for attaching a connecting element (6-9)to an attachment piece (17), a securing element (34), which is guidedthrough an opening (35) in the attachment piece (17), for securing theconnecting element (6-9) on the attachment piece (17) by engaging agroove (36) in the connecting element (6-9), a securing bush (26), whichsurrounds the attachment piece (17) and the connecting element (6-9) atleast partially, for securing the securing element (34), and a springelement (40), which is constructed from a metal spring dip, and which isat least partially supported on the securing bush (26) to hold thesecuring element (34) in the groove (36) in the connecting element(6-9), the securing element is held by a pre-tension force, and thespring element (40) is pushed at least partially in between the securingbush (26) and the securing element (34).
 9. An extension arm accordingto claim 8, characterised in that at least one securing screw isprovided (46), which is screwed into the securing bush (26) and on whichthe spring element (40) is at least partially supported.
 10. Anextension arm according to any one of claims 7 or 9, characterised inthat said at least one securing screw (46) is screwed into the securingbush (26) and engages at least partially in a U-shaped middle portion(41) of the spring element (40).
 11. An extension arm according to anyone of claims 1, 7, or 8, characterized in that the spring element (40)has a first portion (39) and a second portion (42) which, in a relaxedcondition of the spring element (40), are arranged at leastsubstantially perpendicular to one another.
 12. An extension armaccording to claim 11, characterized in that the first portion (39) islonger than the second portion (42).
 13. An extension arm according toclaim 11, characterized in that the second portion (42) is constructedto be such a length that it projects at lest approximately over a loweredge (51) of the securing bush (26) in the assembled condition of theextension arm (1).
 14. An extension arm according to claim 11,characterized in that the first portion (39) and the second portion (42)are connected by a U-shaped middle portion (41) which abuts at leastpartially against the securing element (34).
 15. An extension armaccording to claim 14, characterized in that at least one securing screw(46) is provided, which is screwed into the securing bush (26) andengages at least partially in the U-shaped middle portion (41) of thespring element (40).